Ophiuchus

By BrightK self-checked Published 2026-09-04 Updated 2026-10-18 Editorial policy

• Constellations
• In the sky now

What is Ophiuchus?

Constellations· Summer evenings (N) · a large polygon north of Antares. Asclepius the healer, gripping a serpent. The Sun passes through it every year from late November to mid-December, yet it is not one of the twelve zodiac signs. Barnard's Star, the second-closest star system to us, lies within it.

Stars of the figure

The 2 brightest of the 9 stars used in the figure (9 lines). Lower magnitude means brighter.

Deep-sky objects near this constellation

Constellation basics

Figures are representative approximations. Source: compiled from NASA and IAU public data.

The thirteenth-constellation fuss — a misunderstanding of 2016

In autumn 2016 a story spread around the world that NASA had ‘added’ Ophiuchus as a thirteenth zodiac constellation and changed everyone's horoscope. The source was actually an educational page for children. It simply explained two old facts: that the Sun passes through Ophiuchus, and that astronomical constellations and astrological signs are different things. NASA had changed nothing.

The fuss did help people learn the difference. The twelve astrological signs cut the Sun's path into twelve equal slices of 30 degrees each. The real constellation boundaries, fixed in 1930, are uneven in size. So the Sun spends about 45 days in Virgo but crosses Scorpius in about 7. It spends about 18 days in Ophiuchus.

The constellation in depth

Ophiuchus is Asclepius, the physician of Greek myth, said to be so skilled that he raised the dead. Hades, god of the underworld, complained that his realm would empty, so Zeus killed Asclepius with a thunderbolt, then honoured him with a place in the sky. The snake he holds is a separate constellation, Serpens, and a staff with a snake around it is still the symbol of medicine.

Barnard's Star, inside this constellation, is a small red star, a red dwarf, six light-years away. It moves across the sky faster than any other star: over a human lifetime it shifts by nearly half the width of the full Moon. In 1604 a supernova exploded here. Recorded by Johannes Kepler, it is the last supernova in our galaxy seen with the naked eye.

Ophiuchus faces toward the centre of our galaxy. That is why it holds many globular clusters, and why a dark dust cloud, the Pipe Nebula, hangs like a black shadow against the Milky Way. On summer evenings, look between red Antares in the south and Vega overhead for a wide polygon of modest stars. That is Ophiuchus.

The northern corner of the polygon, Rasalhague, sits right next to Rasalgethi at the head of Hercules. Their Arabic names mean ‘head of the serpent-bearer’ and ‘head of the kneeler’. Set the Sky view to a July night to see the large figure directly above Antares, and switch deep-sky objects to level two to see Barnard's Star marked.

Frequently asked

When can I see Ophiuchus?

Ophiuchus is best seen in summer evenings, June–August.

How do I find Ophiuchus?

To find Ophiuchus, look for the wide polygon between Vega and Antares.

What is the brightest star in Ophiuchus?

The brightest star in Ophiuchus is Rasalhague, at magnitude 2.1.

Related

Figures are representative approximations. Simulated positions use J2000 mean elements.